Mold for manufacturing distillation column packing

ABSTRACT

A distillation column packing in the form of a spherical body constructed by assembling a pair of hemispherical members of the same shape and structure. Each of the hemispherical members includes a suitable number of cutout openings formed in the hemispherical surface portion thereof to leave covering portions, a plurality of mating assembly posts and tubes formed in the hollow inside of the hemispherical member, and reinforcing and gas-liquid contact area increasing contact pieces formed to connect the posts and the tubes with one another but not to close the hollow inside of the hemispherical member. The packing thus constructed is best suited for use in distillation columns.

This is a division, of application Ser. No. 809,329, filed June 23,1977, now U.S. Pat. No. 4,113,810.

The present invention relates to a molding apparatus for making apacking best suited for use in chemical distillation columns, and moreparticularly the invention relates to molding apparatus for making apacking in the form of a spherical body and constructed by assembling apair of hemispherical members each having a specially designed internalstructure.

The distillation process is traditionally known in the art as the methodfor separating the individual components from various mixtures byutilizing the difference in their vapor pressures. In particular, in thechemical industry, a variety of distillation columns have beendeveloped, and paralleling this development many different types ofpackings for filling the insides of such distillation columns have alsobeen developed. For instance, the packings now in wide use include wiremesh packings such as McMahon packing and Dixon packing, wire packingssuch as Helix packing, metal plate, synthetic resin and ceramic packingssuch as Raschig rings, glass packings such as Heli pack, and so on.While, in actual use, a packing of a suitable material, shape andstructure is used by taking into account the type of mixture to bedistilled, the cross-sectional area and packed height of thedistillation column and other conditions, generally speaking the packingused is required to satisfy the following properties in all cases. Thepacking must meet a number of requirements, namely, improved gas-liquidcontact property, reduced pressure drop, elimination of any spacebetween the pieces of packing placed in the distillation column, greaterstrength, lower manufacturing cost, etc. Of the above-mentioned variousknown types of packings, the spherical types have heretofore beenconsidered superior in view of these required properties and have beenused widely. However, so far as is known to the inventor, theseconventional spherical packings are all disadvantageous in that they arecomplicated in construction, are difficult to manufacture and includeportions which are weak in strength so that when a large number ofpieces of the packing are packed in a column, there is the danger thatthe packing pieces will be damaged under the effect of their own weight.

In view of these circumstances, the inventor has developed a moldingapparatus for making a novel spherical packing which eliminates theforegoing deficiencies in the prior art. More specifically, it is anobject of this invention to provide a molding apparatus for making adistillation column packing of spherical shape which is divided into twohemispherical parts so that a desired spherical packing can be veryeasily assembled and constructed by joining together two hemisphericalmembers, each thereof being relatively simple in structure but having ahigh degree of strength and being identical in shape and constructionwith each other, thus permitting their respective projections andrecesses to engage with one another.

It is another object of this invention to provide a molding apparatusfor making such distillation column packing modified in shape andconstruction so that the assembled spherical body can ensuresatisfactory gas-liquid contact, have a sufficient strength and canpractically prevent the occurrence of any filling gap between thespherical bodies packed in a distillation column.

The above and other objects, advantages and features of this inventionwill become more apparent from the following detailed description takenin conjunction with the accompanying drawings, in which:

FIG. 1 is a schematic exploded view showing the construction and mannerof assembly of a pair of the hemispheric members which mate to define aspherical distillation column packing according to this invention;

FIG. 2 is a front view of the spherical distillation column packing madeby assembling the parts shown in FIG. 1.

FIG. 3 is a plan view of the hemispherical member shown in FIG. 1.

FIG. 4 is a plan view of a male mold for making the hemisphericalmembers.

FIG. 5 is a plan view of a female mold adapted for use in combinationwith the male die shown in FIG. 4, as viewed in the arrow direction ofthe line V--V in FIG. 6, and

FIG. 6 is a longitudinal sectional view of the assembled male and femalemolds, as viewed in the arrow direction of the line VI--VI in FIGS. 4and 5.

Referring now to the drawings, the spherical distillation column packing(hereinafter simply referred to as a "spherical body") and itsmanufacturing mold apparatus according to the invention will now bedescribed in greater detail. The spherical body (A) is composed of apair of hemispherical members which are identical in shape andstructure. Thus, for purposes of discussion, only one of thehemispherical members (the upper hemispherical member in FIG. 1) will bedescribed in detail and the other member will not be described. In thedrawings, the identical parts of the two hemispherical members aredesignated by the identical reference numerals.

Referring first to FIGS. 1 to 3, numeral 1 designates a bowl-shapedhemispherical member made of a thermoplastic synthetic resin having itsbottom formed into an open end or face 2 and having a through-hole 3 atits top. Numerals 4, 5, 6 and 7 designate cutout openings radiallyextending from a ring portion 8 on the outer periphery of the hole 3.These cutout openings are formed so as to be arranged alternately withcovering sections 9, 10, 11 and 12 and the openings extend to the midpoint of the outer surface of the hemispheric member 1 to thereby leavean annular wall portion 13 adjacent the open face 2 direction. Numerals14 and 15 designate engaging tubes having corresponding one ends thereofsecured to the inner surfaces of the covering portions 9 and 10 andformed to extend to the annular portion 13. These engaging tubes 14 and15 are positioned slightly inwardly of the hemispherical member 1 withtheir respective extension direction end edges 16 and 17 beingpositioned to be substantially flush with the bottom edge 18 of thehemispheric member 1. Numerals 19 and 20 designate engaging postssimilarly having corresponding one ends thereof secured to the innersurfaces of the covering positions 11 and 12. The posts 19 and 20 arepositioned slightly inwardly of the hemispherical member 1 and have adiameter and shape adapted to be fitted into the engaging tubes 14 and15 and they project outwardly of the bottom edge 18 of the hemisphericmember 1. The engaging tubes 14 and 15 and the engaging posts 19 and 20are provided in the positions opposing one another, utilized forproviding engagement between one subassembly 21 and the othersubassembly 22 which will be described later, and there are of the samenumber. Numerals 23, 24, 25 and 26 designate contact pieces having endedges thereof respectively secured to the engaging posts 19 and 20 andreinforcing posts 27 and 28 of the engaging tubes 14 and 15. The contactpieces 23, 24, 25 and 26 project inwardly of the hemispherical member 1,and their forward end edges are positioned opposite to each other so asto define a suitable facing space 29 formed not to close the inner spaceof the hemispheric member 1. Numeral 30 designates a connection piececonnecting the contact pieces 23, 24, 25 and 26 to one another with thefacing space 29 therebetween, and the connecting piece is formed intocircular shape with a through-hole 31 formed in the central portionthereof.

Next, referring to FIGS. 4 to 6, numeral 32 designates a female moldwith an inlet passage 33 for introducing molten material such asthermoplastic snythetic resin or the like, and the female die includes ahemispherical cavity 34, an inlet port 35 formed in the cavity 34 tocommunicate with the inlet passage 33, a pillar projection 36 formed inthe central portion of the cavity, and a stepped portion 37 and aprojection 38 formed at the outer end of the pillar projection 36 formaking the connecting piece 30. Numeral 39 designates a male dieincluding a centrally formed pillar impression 40 corresponding to thepillar proojection 36 and a hemispherical forming projection 41protruded outwardly so as to correspond to the cavity 34 of the femalemold 32. The male mold 39 is also formed with impressions 42, 43, 44 and45 which are suitably spaced from each other and radially extended fromthe pillar impression 40 as a central axis, and the lower ends of theimpressions 42, 43, 44, and 45 from an annular impression 46 along theouter periphery of the forming projection 41. Numerals 47, 48, 49 and 50designate slits having their upper ends adjoining the impressions 42,43, 44 and 45 and the lower ends vertically extended to the upper planeof the annular impression 46, and also having their inner endscommunicated with the pillar impression 40 and their outer endsrespectively formed with cylindrical engagement impressions 51, 52, 53and 54, of which the engagement impressions 51 and 52 are respectivelyprovided with core projections 59 and 60 to leave suitable feedingspaces 57 and 58 between the inner surfaces thereof and the coreprojections 59 and 60. Numeral 61 and 62 designate impressions forforming the reinforcing posts 27 and 28, which are provided torespectively adjoin the engagement impressions 51 and 52 with the coreprojections 59 and 60, and a sliding hole 64 for a pusher rod 63 isformed to connect with the lower ends of the hole 61.

With the thus constructed male and female molds 39 and 32 fittedtogether, a molten liquid of thermoplastic resin is poured underpressure into the inlet passage 33 for feed material, thus introducingthe molten resin into the mating portions of the male and female molds39 and 32 through the inlet post 35. A filling space 65 defined betweenthe impressions 42, 43, 44 and 45 and the annular impression 46 of themale mold 39 and the inner surface of the cavity 34 of the female mold32 forms covering portions 9, 10, 11 and 12 and an annular portion 13 ofthe hemispheric member 1. The slits 47, 48, 49 and 50 form contactpieces 23, 24, 25 and 26 of the hemispherical member 1, while the pillarprojection 36 forms a facing space 29 at the inner ends of the contactpieces 23, 24, 25 and 26, and the forward end stepped portion 37 andprojection 38 form a connecting piece 30 of the ring with a through-hole31. The engagement impressions 51 and 52 with the core projections 59and 60 form engaging tube 14 and 15 of the hemispheric member 1, and theother engagement impressions 53 and 54 form engaging posts 19 and 20.After the resin solution has cured, the male and female dies 39 and 32are disengaged and the pusher rod 63 is pressed and slid toward theforming hole 61 in any desired manner, thus separating the hemisphericmember 1 from the male die 39 and thereby providing one subassembly 21of a spherical body. By forming in the same way another subassembly 22of the same shape and structure and securely coupling it to thesubassembly 21 by means of their associated engaging tubes 14 and 15 andengaging posts 19 and 20, a spherical distillation column packing isobtained.

Since the distillation column packing of the present invention has aspherical shape, even though a large number of them are packed andrandomly positioned in a packed column, contrary to the case usingpacking materials of square shape, there is no possibility of theindividual pieces irregularly engaging one another thus allowing uniformfilling of the column with the packing, and moreover there is nopossibility of causing a filling gap between the individual pieces. Inaddition, the provision of the cutout openings and through-holes has theeffect of minimizing the pressure drop and preventing the liquid fromremaining within the spherical bodies, and moreover the vapor can enterinto the spherical bodies thus allowing both surfaces of the sphericalbodies to entirely serve as liquid-gas contact surfaces. Further, theprovision of the contact pieces has the effect of increasing thegas-liquid contact area and increasing the free volume. Still further,the fact that the contact pieces are connected with one another by theconnecting piece has the effect of increasing the resistance of thespherical bodies against externally applied forces and also preventingdeformation of the spherical bodies packed in the lower portion of thepacked column. Still further, since the pair of subassemblies of thespherical body are of the same shape and structure and adapted to befitted and fastened to each other by means of their associated engagingtubes and posts, only one type of mold device is required formanufacturing the necessary packing and the products thus obtained arealso inexpensive.

Still furthermore, since the engaging parts of the male and female diesof this manufacturing apparatus are reduced to ensure a simplecombination, the desired packing can be quickly manufactured with thesimplified shapes.

What is claimed is:
 1. An apparatus for manufacturing one subassemblywhich can be joined to another subassembly of the same structure to forma spherical distillation column packing, comprising: a female mold parthaving a hemispherical cavity and an inlet port for feeding moldablematerial into said cavity, said female mold part having a pillarprojection extending diametrically from the center of the wall of saidcavity toward the open end of said cavity; a male mold part extendingacross and closing off the open end of said cavity, said male mold parthaving a generally hemispherical forming projection extending into saidcavity, said forming projection having a central opening for receivingsaid pillar projection, said forming projection having surface portionsopposed to the wall of said cavity and defining therewith a hollowgenerally hemispherical mold recess shaped to define a plurality ofcutouts and covering portions formed alternately in the side surface ofsaid mold recess, said forming projection also having means to form anengaging tube on the inner surface of one of said covering portions andprojecting toward the open end of said cavity, said forming projectionalso having means to form an engaging post on the inner surface of adifferent one of said covering portions which post is shaped to fit intothe engaging tube of another like subassembly, said forming projectionalso having means for forming a plurality of contact pieces which areintegral with said engaging tube and said post respectively and whichextend toward the center with their adjacent ends being spaced from eachother, said pillar projection and said central opening of saidprojecting portion defining a space for forming a connecting piececonnecting the inner end edges of said contact pieces with one another.